Carrier chains used in decorative coating processes are used specifically to carry coated containers through heating and treating ovens where extreme temperatures are encountered. High speed travel is necessary to produce high productivity.
In oven applications, chains display rapid elongation caused by temperature changes and speed of the chain/sprocket engagements, and wear between pins and bushings.
There exists a need for an extended life chain for oven applications, and further for applications where chains are exposed to extreme conditions, such as heat and increased speed. Roller chains are known to improve the smoothness of operation and to extend the life of chains. Increased bearing areas between pins and bushings for chain-life prolongation are explained in detail in U.S. Pat. No. 4,571,229. However, it has previously not been practical to use chains with larger bearing areas in combination with rollers, because conventional rollers would have changed dimensions to such an extent that they would not be usable with existing equipment.
It is an object of the present invention to overcome deficiencies of the prior art and to provide extended life for roller chains for use in decorating ovens.